1. Field of the Invention
The present invention relates generally to devices which are utilized to apply surgical clips and, more particularly, to such devices having a jaw capable of receiving tissue and applying a self-closing clip adapted to replace a suture knot during laparoscopic or endoscopic surgery.
2. Description of Related Art
As medical and hospital costs continue to increase, surgeons are constantly striving to develop advanced surgical techniques. Advances in the surgical field are often related to the development of operative techniques that involve less invasive surgical procedures and reduce overall patient trauma. In this manner, the length of hospital stays and patient recovery can be significantly reduced, and therefore hospital and medical costs can be reduced as well.
Suturing is a procedure that surgeons are required to perform to repair or reconstruct traumatized body tissue. Medical instruments have been recently designed to allow a surgeon to manipulate a suture, or suture and needle combination, through the small diameter opening of a cannula. However, the ability to tie an appropriately placed suture may be problemsome in certain confined spaces.
One advance in recent years to reduce the evasiveness of surgical procedures is endoscopic surgery. Endoscopic surgery involves the use of an endoscope, which is an instrument permitting the visual inspection and magnification of a body cavity. The endoscope is inserted through a cannula after puncture through a wall of the body cavity with a trocar assembly that includes a sharp-pointed obturator interfitting in the cannula. After removing the obturator, the surgeon can perform diagnostic and therapeutic procedures at the surgical site with the aid of specialized instrumentation designed to fit through additional the cannula. Fore some procedures, multiple trocars providing small diameter openings into the desired body cavity may be required.
Increased versatility of endoscopic staple and clip applying mechanisms enhance the effectiveness of endoscopic procedures. These mechanisms are placed through a cannula of an endoscopic trocar so that the tissue may be cut, stapled or ligated. With the advent of these devices, however, there have been certain noted inadequacies. Many of these inadequacies have become perceived solely because of the newness of the endoscopic procedures.
It is known in the art to use hemostatic clips and clip appliers to ligate blood vessels and other tubular members. Such hemostatic clips and clip appliers are described, for example, in U.S. Pat. Nos. 4,418,694, 4,476,865, 5,030,226, 5,163,945, 5,171,249, and 5,439,468. In performing a ligating procedure with these types of clip appliers, the jaws physically deform a clip about a vessel or tissue to be clamped or ligated.
Additionally, the use of a surgical clip applier combined with a special self-closing surgical clip has been demonstrated in U.S. Pat. No. 5,601,573. However, the surgical clips utilized by this clip applying device must have special tabs which cooperate with special rails and special shelves within the jaws of the device in order to separate the special self-closing surgical clip. This instrument does not allow the operator to view the clip while deploying it to a desired location.
In view of the deficiencies of the prior art for creating a useful endoscopic alternative to tying a suture knot, what is desired within the medical community is a device suitable for application using endoscopic techniques to successfully replace the suture knot. More specifically, what is needed is a surgical clip and clip applier system particularly adapted for replacing a suture knot during endoscopic surgery which allows the surgical clip to exhibit adequate clamping force to function effectively.
A surgical clip particularly adapted for use with the present invention is a clip constructed of a memory shape material, such as is utilized in a preferred embodiment of commonly assigned U.S. patent application Ser. No. 09/120,450. Memory shape materials may include compositions of nitenol, stainless steel, or any other composite of plastics, metals and/or resins. In order to more readily apply a surgical clip using endoscopic techniques, it is desired to provide an improved surgical clip applier.
For instance, there has been perceived a need for an improved clip applier capable of using self-closing surgical clips. Presently, prior art clip appliers such as the one described in U.S. Pat. No. 5,601,573 are constructed in such a manner that the clip applier has a jaw portion which obscures the surgical clips it applies. In fact, a window has been built into the upper jaw to compensate for the lack of visibility within these jaws. In performing a ligating procedure with this type of clip applier, the surgeon, or other operator, cannot easily see a surgical clip within the jaws of the clip applier to verify that the surgical clip has not become dislodged. If the window does not happen to be directly in a surgeon's line of sight, the surgeon will not be able to see whether a clip was loaded until the jaws are released from the closed position. If a clip was not loaded, the surgeon will need to grasp the tissue again and retry the clip applying process.
Another perceived problem with the design taught by the '573 patent is the direct exposure of the surgical clip to a tissue which is being ligated during the application process. During the application process, the clip is pushed distally into the jaws and onto the tissue. The first and second legs will contact the tissue as the clip enters the jaw as the clip is internal to the workings of the jaw, i.e., the jaw acts to pull the first leg away from the second leg using special rails, special tabs, and special shelves. Any imperfection in the legs of the clip, including the dimples taught by the '573 patent, may cause abrasion or damage to the tissue during the application process. Additionally the use of tabs with rails requires increased precision of tolerances, complexity, and cost in the manufacture of both the jaws of the clip as well as each individual surgical clips. If a clip is incorporated into the applicator which does not meet the tolerances required to fit within the special rails and shelves, the applicator will be jammed.
One other perceived problem with the design of the '573 patent is the initial unequal distribution of force along a tissue. Notice in FIG. 5D that when the clip applier applies the clip, the first and second legs form a V-shape. This V-shape of the leg members will result in an initial unequal distribution of force along the application tissue.
There is a perceived need to provide a surgical clip applicator which protects a tissue for a substantial portion of the application process.
There is another perceived need for a surgical clip applicator which provides improved visibility during application and which can utilize simply designed clips.